Safety reel for blasting cables



Acs. T. ATKxNs 2,205,056

SAFETY REEL FOR 'BLASTING CABLES Find April 14, 193sV me/who@ Patented June 18, 1940 unire stares ATENT QFFiCE 3 Claims.

This invention relates to the class of winding and reeling and pertains particularly to improvements in reels designed especially for carrying electric' cables used in blasting operations.

in the operation of blasting, electric cables are run from the blast charge or detonator to an electric battery which is employed for setting off the charge and it is a common practice to use cables having free ends which makes the operation particularly hazardous because of the fact that it is possible to fire the blast charge when the operator is only a few feet away from the same,

lThe present invention has for its primary object to provide a blasting cable reel which is so designed that all of the cable must be unwcund therefrom before the battery can be connected with the end of the cable to eiect the ring o the blast charge.

Another object of the invention is to provide, more specifically, a blasting cable reel which has a center cylinder on which the cable is wound, in which is located a pair of terminals having the ends of the cable connected thereto, against which the two poles of the liring battery are placed in the process of ring a blast charge, and these terminals are kept covered and are protected so long as any cable remains wound upon `the reel.

A still further object of the invention is to pron vide an improved blasting cable reel having cer.- tain novel features of construction whereby the terminals of the blasting cable are kept protected against connection with the firing battery so long as the cable is wound upon the reel and which is of relatively Simple but strong and durable construction.

The invention will be best understood from a consideration of the following detailed description taken in connection with the accompanying drawing forming part of this specification, with the understanding, however, that the invention is not confined to any strict conformity with the showing of the drawing but may be changed or modified so long as such changes or modifications mark no material departure from the salient features of the invention as expressed in the appended claims.

In the drawing:

Fig. 1 is a sectional view taken through the reel structure embodying the present invention on a line perpendicular to the rotary axis of the reel.

Fig. 2 is a vertical sectional View taken on the line 2-2 of Fig. 1.

Referring now more particularly to the drawing, the numeral l generally designates the frame for the reel structure embodying the present invention, which frame consists of the pair of side supporting units 2, each of which is in the form of an inverted V having an aperture at the apex for the passage of the reel carrying shaft 3 and having the free ends of the two side portions connected with the ends of the opposite unit by the transverse connecting bars 4.

The reel unit which is mounted upon the shaft B is indicated generally by the numeral 5 and comprises the two side disks 6 which are connected by the drum l and the transverse bolts 8 which pass through the disks and through the drum and serve to draw the disks together against the ends of the drum.

The drum 'l is arranged coaxially with the axle shaft Si and the outer side of each disk 6 has secured thereto a plate 9 through which the shaft passes and which is preferably welded to the shaft.

The numeral i0 ,designates a bushing or sleeve which surrounds the shaft t at each end of the reel and serves as a spacer between the reel and 'L the adjacent ground engaging supporting unit 2, and these sleeves may either be loose upon the shaft or they may be welded to the adjacent plates 9, as may be found desirable.

The cylinder l has a door opening il formed therethrough, the opening extending lengthwise of the cylinder as shown and terminating short of the end disks S. This opening has a metal door i2 fitted therein, the door preferably being made of copper and one longitudinal edge of the f door has secured thereto a hinge leaf I3 which is connected by a hinge pintle i4 with a cooperating leaf l5 which is secured to the side of the drum adjacent the edge of the door opening, v

The shaft 3 has a portion of its length lying within the drum 'l flattened as indicated at I6, and secured upon this flattened portion and extending longitudinally of the shaft are the two elongated blocks of insulation material which are indicated by the numerals il and I8. These blocks are secured together and to the shaft by means of the bolts I9 which pass through the three elements and the outer one of the two blocks, that is, the block which is indicated by the numeral i8, has extended therethrough the two relatively long contact pins 20. The inner ends of these pins may be headed and when the blocks l'l and IS are in assembled relation, these inner ends of the pins will bear against the adjacent face of the inner block Il.

Bearing against the outer side of the outer block I8 and threaded upon each of the contact pins are securing nuts 2| and binding nuts 22. The securing nuts serve to retain the contact pins in position While the binding nuts are employed for binding or securing to the pins the ends of the Wires 23 of the blasting cable which is indicated generally by the numeral 24 and which passes out from the interior of the drum through an opening 25 which is formed in the wall of the drum as shown.

The contact pins 2D are of such a length that when the metal door i2 is closed, it will engage the outer ends of the pins and thus form a metallic contact between the same.

Upon the inner side of the door i2 and adjacent each end of the same there is secured an ear 2B to which is attached one end of a contractile spring 27, the other end of the spring extending inwardly to and having connection "1th the shaft 3. By this it will be readily seen that the metal door is normally securely held closed so that a positive act must be performed in uncovering the Wire terminals to permit the electric battery to be coupled therewith.

One end of the shaft 3 is shown as being bent to f crm a crank 2S by means of which the drum may be rotated so that the cable 2t may be wound up thereon.

From the foregoing it will be readily apparent that before the blasting cable can be employed for setting ofi" a blasting charge Which is coupled with the free end thereof, the entire amount of the cable must be unwound from the drum so that the door 52 can be opened to espose the contact pins s0 as to permit the electr'cal connection of these pins and the ends of the cable wires 23 with the blasting batteryv After the door is opened, the blasting battery is placed down upon the pins 2Q so that they will be made to form an electric Contact with one of the two poles of the battery and thus supply the necessary current to the cable to set off the blasting charge which is connected with the other end thereof.

What is claimed is:

i. A blasting cable reel structure of the character described, comprising a rotatably mounted supporting shaft, a reel drum carried upon the blaft and including a central 'body supported coaxially with the shaft to be rotated thereby, the body being formed to provide a chamber through which the shaft extends, the body having an opening for the extension of an end of an electric cable which is wound on the drum from outside the body into the chamber, said body having a wall opening leading into the chamber which is covered by the cable when the latter is wound on the body, a pair of rigid terminal pins mounted Within the chamber upon said shaft and extending radially therefrom toward and terminating substantially in said wall opening, said terminal pins being insulated from the shaft and from one another and each being adapted to be electrically connected with one of a pair of wires forming the cable, and a door closing said Wall opening and bearing against the ends of said pins and establishing an electrical connection between the free ends of said pins.

2. A blasting cable reel structure of the character described, comprising a rotatably mounted supporting shaft, a reel drum carried upon the shaft and including a central body supported coaxially with the shaft to be rotated thereby, the body being formed to provide a chamber through which the shaft extends, the body having an opening for the extension of an end of an electric cable which is Wound on the drum from out side the body into the chamber, said body having a wall opening leading into the chamber which is electrically connected with one of a pair of wires forming the cable, and a removable electrical connecting means between the ire-e ends of said pins and lying within the opening and covered by the cable When the latter is Wound on the drum.

Il. A blasting cable reel structure of the character described, comprising a rotatably mounted 'n supporting shaft, a reel drum carried upon the shaft and including a central body supported coaxially with the shaft to be rotated thereby, the body being formed to provide a chamber through which the shaft extends, thc body having an opening for the extension o an end of an electric cable which is Wound on the drum from outside the body into the chamber, said body having a Wall opening leading into the chamber which is covered by the cable when the latter is wound on the body, a pair of rigid terminal pins mounted Within the chamber upon said shaft and extending radially therefrom toward and terminating substantially in said Wall opening, said terminal pins being insulated from the :shaft and from i one another and each being adapted to be electrically connected with one of a pair of Wires forming the cable, a metal door pivotally secured to the body to close said Wall opening and adapted when closed engaging and electrically coupling together the free ends of the pins, and spring means connected with said door and constantly urging the same to closed position.

GEORGE THORNTON ATKINS. 

